Fiberglass mats are used as a heat and sound insulating material in automobiles, and as heat and sound insulation in a variety of other products, including duct liners. The use of traditional fiberglass mats for some applications has recently decreased due to various perceptions, correct or not, regarding their safety and stability. For example, fiberglass duct liners are being de-specified by schools, hospitals, and some government agencies. It has been suggested that fiberglass duct lining materials may capture and hold dirt in the duct and provide a food source for mold and bacterial growth. Additionally, it has been suggested that fiberglass may capture and retain moisture in duct systems, providing a water source for mold and bacterial growth. Finally, it has been suggested that fiberglass may erode in the duct and be blown or emitted into the workspace. Such perceptions continue, in spite of evidence to the contrary, and have the effect of reducing the use of conventional fiberglass duct liners.
Alternatives to fiberglass for use in duct linings include elastomeric foam/rubber or cotton-based products. Though elastomeric foams may be hydrophobic and thus provide a less hospitable environment for mold and bacteria, they often exhibit poor sound absorption characteristics, leading to noisy workplace environments. Although the transmission of noise can be reduced by the insertion of acoustic baffles in the ductwork, such baffles may also tend to restrict airflow, resulting in reduced blower capacity and increased air handling costs. Furthermore, the thickness of elastomeric foams is limited to less than about one inch, due to its propensity for smoke development and flame spread in a fire. Cotton-based products have the desirable property that they can be prepared as a recycled product, but they are typically treated with fire retardant and anti-microbial agents to allow their use in ducts. However, the long-term efficacy of these treatments is questionable, because cotton material is a food source for molds, and fire retardants may migrate with water and gravity.
The present disclosure describes a fiberglass article that includes a fiberglass product that is covered within a flexible, polymer envelope. In addition, the present disclosure describes a fiberglass article that includes a layer of fire resistant material in conjunction with the plastic cover or the fiberglass component. It is appreciated that fiberglass articles described herein are stable and retain the heat and sound insulating properties of traditional fiberglass with acceptable or enhanced fire performance characteristics.